The Science of Training Volume: How Much is Enough for Muscle Growth?

Muscle hypertrophy, or muscle growth, is a common goal among athletes, fitness enthusiasts, and bodybuilders. One of the most crucial aspects influencing hypertrophy is training volume, defined as the total amount of work performed during a training session or over a given period.

Volume is considered a primary factor influencing muscle hypertrophy since it dictates the total mechanical tension a muscle is exposed to, which is essential for stimulating growth. However, volume needs to be balanced with recovery to avoid overtraining and injury.

Training volume is often expressed as the number of sets multiplied by the number of repetitions, but can also include considerations of load, frequency, and intensity. The key question is: how much training volume is optimal for maximising muscle growth?

Training volume in resistance training can be broken down into several key variables: 

The total number of sets per muscle group or exercise.

The number of repetitions performed in each set.

How often a muscle group is trained, typically per week.

However, for this article, we will define training volume as the total number of sets taken to/close to failure per muscle group or exercise. This is because training to/close to failure is key for building muscle, and so we will only consider these sets when determining training volume.

Whilst low volume training may not be as effective as moderate or high volume training for hypertrophy, individuals can still make significant gains, especially those with less training experience (Androulakis-Korakakis et al., 2020).

Low volume training is also useful for those who have limited time to train each week, as long as sets are pushed close to failure.

Moderate volume training is very effective for hypertrophy. Performing 10-19 sets per week allows for a significant hypertrophy stimulus, whilst also allowing for sufficient recovery during the training week.

A meta-analysis by Schoenfeld et al. (2017) found that individuals performing 10+ sets per muscle group per week experienced significantly greater muscle growth than those performing fewer than 5 sets.

Some evidence suggests that very high-volume training (more than 20 sets per week per muscle group) can continue to provide benefits, particularly for advanced athletes. However, the benefits start to plateau, and in some cases, excessive volume can lead to overtraining and diminishing returns (Schoenfeld et al., 2017).

Within-session training volume refers to the number of sets performed per muscle group in a single training session. While weekly training volume (total sets per week) plays a crucial role in muscle hypertrophy, recent research highlights that the distribution of volume across training sessions is also key. 

Within-session volume is integral to hypertrophy because it determines the immediate mechanical tension a muscle group experiences. However, the relationship between within-session volume and muscle growth is complex. Piling on too many sets in a single session is unlikely to yield additional benefits due to fatigue accumulation and a reduction in force output.

Recent evidence supports the idea of “diminishing returns” where excessive within-session volume could even hinder growth due to compromised quality of movement and recovery.

Low volume per muscle group can be very effective as long as training frequency is high, and overall weekly training volume is optimal. This is because low volume training allows for sufficient recovery of individual muscle groups between training sessions, meaning they can be trained hard multiple times per week.

Moderate volume per muscle group per session is typically most effective for muscle growth as it allows for a maximal hypertrophy stimulus. Whilst fatigue will be higher compared to lower volumes, it will still be manageable enough and ensure sufficient recovery (Schoenfeld et al., 2019).

Once volume per muscle group per session exceeds 8 sets, typically, fatigue will begin to outweigh the hypertrophy stimulus.

This is because each additional set performed per muscle group leads to less hypertrophy and more fatigue. In other words, the first set stimulates the most hypertrophy and the least fatigue compared to subsequent sets.

Therefore, performing more than 8 sets per muscle group per workout is suboptimal and will result in excessive fatigue (Grgic and Schoenfeld, 2018).

While increasing training volume can stimulate greater hypertrophy, more is not always better. Excessive volume, especially when combined with insufficient recovery, can lead to overtraining, injury, and stagnation in progress.

Recovery is influenced by factors such as sleep, nutrition, and stress management, and must be prioritised alongside training.

To manage volume effectively:

Keep track of strength levels and overall fatigue. If performance starts to decline consistently, it may be a sign that your training volume is too high.

Periodically reducing training volume for a week (known as a deload) can help reduce fatigue and enhance recovery, allowing for greater long-term progress. 

Adjust training volume based on individual recovery ability and lifestyle factors. Not everyone can tolerate the same amount of training volume due to differences in genetics, work stress, and other external factors. 

Optimising training volume is a nuanced and highly individualised aspect of achieving muscle growth. While research supports a moderate weekly volume for most individuals aiming for hypertrophy, the exact volume required depends on factors such as training experience, recovery capacity, and personal goals.

Low volume training can still be effective for beginners and those with time constraints, while advanced athletes may benefit from higher volumes, though with diminishing returns as volume increases.

Within each session, balancing volume is essential to maximise the hypertrophy stimulus without incurring excessive fatigue.

Androulakis-Korakakis, P., Fisher, J.P. and Steele, J., 2020. The minimum effective training dose required to increase 1RM strength in resistance-trained men: a systematic review and meta-analysis. Sports Medicine, 50(4), pp.751-765.

Schoenfeld, B.J., Ogborn, D. and Krieger, J.W., 2017. Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. Journal of sports sciences, 35(11), pp.1073-1082.

Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2019). “Effect of weekly set volume on strength gain: A meta-analysis.” Sports Medicine.

Grgic, J., & Schoenfeld, B. J. (2018). “Are the Hypertrophic Adaptations to High and Low Load Resistance Training in Humans Influenced by Changes in Muscle Architecture?” Sports Medicine.